@Vertiginous and I were talking a week ago, and he mentioned installing outlet insulators in his apartment. Ignoring the fact that he’s allowed to actually make improvements to his apartments, and I think I would have been evicted had any of my landlords discovered that I so much as took the outlet covers off, it’s worth suggesting that there are a range of small, cheap improvements you can make to your house to improve insulation in the winter.
The outlet and light switch insulators go under the covers and help keep drafts out. How much does this matter? It depends on the house, but they’re a large gap in the otherwise hopefully solid insulation, so they can make a difference - I’ve seen 2-5% numbers, depending on the house, which isn’t too bad for a couple bucks.
I picked up my kit from here: Electrical Outlet & Light Switch plate Foam Gasket Insulator Kit | Weatherization & Winterize
Mostly because I’m trying to get away entirely from Amazon, and if I need something, I’m trying to order from independent stores rather than eBay (which, depressingly often, ends up being an Amazon drop shipment).
I also picked up a few of these: Brass Door Tite Strike Plate Ratchet Style Door Strike Hardware Jamb| Automatic Door Tight
They help keep doors closed more tightly, and seem to do a good job of it.
Will it make a huge difference? Probably not. But it’s likely to make some moderate difference, and it’s the sort of “low cost, low effort” solution that does make some very concrete reductions in energy use in a typical home.
Next step is probably to start handing the kits out at church to people who are interested.